The Fabrication Of MoS₂-based Nanocomposites And Performance For Electrochemical Hydrogen Evolution

With the rapid growth of economy,the demand of energy is constantly increasing in modern society,the problems of energy crisis and environmental pollution have become more serious,it is imperative to develop green and sustainable energy.Among these,the hydrogen energy can be widely regarded as alternative energy due to a series of advantages and has been caused widely attention,with a series of hydrogen production technology produced,meanwhile,electrolysis hydrogen production is one of the effective ways to make hydrogen because of its simple operation and no pollution.The best efficient catalyst for HER is the Pt-group noble metals,but the large scale applications have been restricted due to its expensive and limited resources reserves.Therefore,the development of catalysts of low cost and high catalytic activity is important research directions in this field.Molybdenum disulfide,a typical representative of transition metal sulfide,has demonstrated excellent electrocatalytic hydrogen evolution performance,to be an alternative catalyst of precious metal.But molybdenum disulfide is a kind of semiconductor material,which leads to poor conductivity,and easy to reunite,so that the number of active sites for hydrogen evolution is decrease.Therefore,Based on the improving the defects of molybdenum disulfide,the research contents of this subject are divided into two parts:1.The combination of molybdenum disulfide(MoS2)and N-doped macro-mesoporous carbon(N-MMC)was achieved successfully by hydrothermal method with adjusting the mass ratio of precursors,meanwhile,exploring the performance of catalytic activity of hydrogen evolution of molybdenum disulfide/N-doped macro-mesoporous carbon(MoS2/N-MMC)composite material.The specific research contents are as follows: sodium molybdate as the source of molybdenum,thiourea as the sulfur source,hydrazine hydrate(reducing agent),DMF as solvent,nitrogen doped macroporous mesoporous carbon acted as substrate material for the growth of molybdenum disulfide,and the three-dimensional nanocomposites of ultrathin molybdenum disulfide nanosheets on the surface of nitrogen-doped mesoporous carbon was prepared.The properties of hydrogen evolution were studied by electrochemical test.2.Zinc,molybdenum disulfide and N-doped graphene were combined by a one-step hydrothermal method,and the electrochemical properties of Zn-MoS2/NG were investigated.Concrete research is as follows: ammonium tetrathiomolybdate as a source of molybdenum and sulfur,hydrazine hydrate as reductant,zinc nitrate with zinc atom,and the zinc doping molybdenum disulfide compound nitrogen doped graphene nanocomposites were successfully prepared.The hydrogen evolution performance of Zn-MoS2/NG composites via electrochemical testing.The morphology and structure of the above mentioned composites were analyzed by physical characterization.The performance of electrocatalytic hydrogen evolution was characterized by electrochemical test.The results show that the materials have low initial overpotential and Tafel slope,large current densit and good stability.These works for the design and synthesis of other hydrogen cathode materials provide a new direction.